Over the years a considerable number of undersea transducer designs have evolved and, although their applications and configurations have varied, all seem to rely on some sort of an acoustic window that functions as a covering or separation that, at least, partially protects the transducer from the harsh marine environment. The acoustic window should be a cost-effective, producible design that is capable of acceptably transmitting acoustic energy while being rugged enough to withstand the rigors associated with varying velocities of flowing water, fluctuating temperatures, changing ambient pressures, the abuse attendant operations, etc., that are routinely encountered during a prolonged deployment.
One acoustic window design/method used a dacron fabric reinforced modified syntactic epoxy prepregnated material. The method of manufacture for the window design/method involves a costly pressure/autoclave process requiring a relatively long production time. There is some conjecture that the original acoustic window design is stiff and does not conform easily to the slight contour of the mounting plate form and is sometimes damaged during installation. The window material, near the outer perimeter was provided with twelve countersunk clearance holes for the mounting bolts to be inserted therethrough. When excess torque is applied to any of the mounting bolts, the adjacent window material can be over stressed which might compromise the acoustic properties or the mechanical integrity.
Thus, there is a continuing need in the state of the art to provide a cost effective acoustic window having acceptable acoustical and mechanical properties over a wide range of operational conditions.